Chemo‐ and Regioselective Reduction of 5,15‐Diazaporphyrins Providing Antiaromatic Azaporphyrinoids |
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Authors: | Ayaka Yamaji Prof?Dr Hayato Tsurugi Prof?Dr Yoshihiro Miyake Prof?Dr Kazushi Mashima Prof?Dr Hiroshi Shinokubo |
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Institution: | 1. Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Japan;2. Department of Chemistry, Graduate School of Engineering Science, Osaka University, Osaka, Japan |
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Abstract: | Reagent‐controlled chemo‐ and regioselective reduction of 5,15‐diazaporphyrins has been developed. The selective reduction of carbon–carbon double bonds of diazaporphyrins provides 18 π aromatic isobacteriochlorin‐type products, whereas the reduction of carbon–nitrogen double bonds leads to selective formation of 20 π N,N′‐dihydrodiazaporphyrins in excellent yields. The distinct antiaromatic character of N,N′‐dihydrodiazaporphyrins has been revealed. The free‐base N,N′‐dihydrodiazaporphyrin exhibits slower inner NH tautomerism than that in the corresponding 18 π porphyrins. |
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Keywords: | antiaromaticity chemoselectivity porphyrinoids reduction tautomerism |
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